1. Field of the Invention
The present invention relates generally to hydraulic valves. More particularly, the present invention relates to a hydraulic spool valve having an internal helical actuator.
2. Related Art
Spool valve manifolds are used to accomplish opening and closing of ports, such as for directing hydraulic fluid to various hydraulic devices. These types of manifolds are frequently used in aircraft, for example, to selectively direct hydraulic fluid between actuators for ailerons, flaps, rudders and other flight surfaces, as well as actuators for landing gear, thrust reversers, and other hydraulic devices.
Current spool valve manifolds tend to be relatively large and heavy. They are typically long in order to accommodate a number of ports that are sequenced in-line (e.g. neutral, open, & closed positions). This length and size gives them a fairly large volume. These types of valves also tend to be heavy because they are often machined from solid metals, such as titanium. The size, weight and volume of typical hydraulic spool valve manifolds is a concern in the field of aviation and other applications of these types of valves.